1. Technical Field
The present disclosure herein relates to methods for fabricating semiconductor memory devices and, more particularly, to methods for fabricating phase change memory devices.
2. Description of Related Art
With the recent trends toward higher integration of semiconductor devices, memory cells are increasing in number and decreasing in size. Accordingly, wordlines and bitlines connected to the memory cells are increasing in length and number, which may lead to an increase in wordline and bitline capacitances. As a result, semiconductor memory devices may encounter a limitation in achieving high speed and low power consumption.
As an approach to realize higher performance and lower power consumption, next-generation memory devices are being manufactured that do not have refresh operations, in contrast to semiconductor memory devices such as volatile, dynamic random access memory (DRAM). An example of such a next-generation memory device is a phase change random access memory (PRAM), which uses phase change material. Accordingly, there is a need for process development which makes it possible to fabricate phase change memory devices with beneficial electrical characteristics and increased process margin.